Certain types of beverage containers, such as bottles and cans, are made of recyclable materials such as aluminum, glass, or plastic. These containers can often be redeemed by consumers for money or other forms of compensation, wherein the redemption value is typically calculated on a per unit basis. Sometimes, the redemption value may be calculated by weight, but this method may result in inaccurate redemption values or require more work by consumers and redemption centers. For example, the presence of fluid in containers would increase the overall weight and redemption value of a collection of containers beyond their actual redemption value. In addition, the redemption value of different materials of equal weight may differ, and thus require consumers or redemption centers to take the extra step of sorting containers by material composition (e.g., glass, plastic, metal) before they are weighed.
Calculating the redemption value of containers on a per unit basis avoids these aforementioned issues but comes with its own set of issues. Manual counting of containers is time-consuming and labor-intensive. Furthermore, counting containers by hand, especially large quantities, is prone to errors. Some redemption centers tell their customers they don't need to pre-sort the containers, thus offering to sort the containers for the customer. Conventional sorting usually involves dumping the containers on the ground and then the worker has to grasp each container and toss it into a bin. This is called floor sorting, and requires the worker to work in bent over or crouching positions. Such sorting procedures are generally slow, inefficient, inaccurate, and physically taxing on the worker.